I was an original Kickstarter Backer, the game is much like Elder Scrolls Online in that you buy in a package and then get to play without further sub fees. That siad there is a subscription you can do that currently provides early access to news about the game as well as certain flair in the form of limited edition in game items that you can display in your hanger. Other than that there's a ton of cash store items and ships you can buy. Some of which are useable in the game now and some of which won't kick in till it launches. One of the things to also keep in mind is that according to the Devs anything that you can buy from the cash store will eventually be buyable with ingame currency that you earn so there's no pay to win going on.

If you just wanna give it a roll it's easy to buy one of the starter packs for the 40 dollar range, you can then upgrade your starter ship at any time if you wanna invest more in the game. They also run sales and such around the holidays so if you buy in and are patient you can probably grab a cheap upgrade at some point too.